/*
 *   Copyright 2013 Peter G. Horvath
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */
package org.magni.concurrent;

import java.util.concurrent.Callable;

class CallableLazyInitializer<T> extends Lazy.Initializer<T> {

	private final Callable<T> initializer;

	CallableLazyInitializer(Callable<T> initializer) {
		if(initializer == null) {
			throw new NullPointerException("initializer must not be null");
		}
		this.initializer = initializer;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.magni.concurrent.initializer.LazyInitializer#initializeValue()
	 */
	@Override
	protected T initializeValue() {
		try {
			return initializer.call();
		} catch (RuntimeException e) {
			throw e;
		}
		catch (Exception e) {
			throw new LazyInitializerException(
					"Lazy initializer threw exception",	e);
		}
	}

}